BTO migration blog

Spring and autumn are exciting times for anyone who watches birds. Here on this blog we will make predictions about when to expect migrant arrivals and departures, so that you know when and where to see these well-travelled birds.

Friday, 28 September 2012

The perfect storm

Having been stuck in a westerly airflow for what has seemed like forever, the weather forecast, with the promise of a depression swinging south of the UK and heading north into Scandinavia looked too good to be true. The resultant easterly winds, coming straight out of Scandinavia and western Russia, just had to bring some eastern birds with them.

Birders were not to be disappointed. In fact the storm headed north earlier than was predicted and crossed right over Britain and Ireland, initially producing strong westerlies that turned into strong easterlies as it moved on north and west, as predicted eastern birds seemed to drop out of the sky. Weighing around 6g, over 100 diminutive Yellow-browed Warblers were found from Shetland to the Isles of Scilly. Yellow-browed Warbler breeds no closer to Britain than eastern Russia, with the majority breeding much further east. Rather than heading west into Europe these birds should have been making their way south and east into south and eastern Asia. Joining these were one or two other eastern delights, up to four Lanceolated Warblers that should have been on their way to a similar area, and a couple of Booted Warblers that winter in India were two. However, pride of place must go the White’s Thrush that was found on the Farne Islands, this amazing thrush winters in China. As the storm tracked towards Scandinavia it also brought birds from there too. Around 100 Red-breasted Flycatchers and over fifty Barred Warblers graced our shores over the weekend.

Yellow-browed Warbler by Joe Graham

The westerly theme of the last few weeks was not to be left out completely. As the storm left American shores and crossed the Atlantic it brought with it Britain’s second ever Magnolia Warbler, and a Swainson’s Thrush, both to Shetland.

Common migrants also abounded with the largest fall of Goldcrests, Redstarts and Robins of the autumn so far. The BirdTrack weekly reporting rate for Redstart shows this nicely. Thrushes were also on the move with the first noticeable arrival of Redwings, Fieldfares and Song Thrushes. As more birds arrive and more people take part in the Winter Thrushes Survey, it will be interesting to see how they move through the country.

Redstart by Edmund Fellowes

So what will this weekend bring? The focus will once again turn to the west and north-west, where the next transatlantic storm will arrive, maybe bringing with it more goodies from North America. A Black-billed Cuckoo is long-overdue and would prompt many a birder to head west.